Interpretive Summary: Long-term, large-scale integrated pest management/integrated crop management (IPM/ICM) field studies are important research projects. They identify profitable cropping systems, provide information on cumulative treatment effects, assess conservation tillage systems, and identify strategies for erosion control and pest management. Long-term, field scale estudies are generally inter/multidisciplinary and involve several agencies In the past these studies were not routinely conducted because they require large areas of land, are very expensive to conduct, and need a considerable labor force to conduct the research. However, more of these studies are being conducted throughout the Untied States to provide important agroecosystem information to growers and researchers. From 1985 to 1991 a long-term IPM/ICM study was conducted in the Pacific Northwest to identify economically feasible and environmentally sound conservation cropping systems for adoption by regional growers. It as a complete study that involved more than a dozen scientists, form eight disciplines, representing four agencies and encompassing 80 acres. The present study has reanalyzed the 6-yr project to determine the effect of reducing (downsizing) the size and duration of cropping systems studies on the yield (biological) and economic data collected. Economic and biological data were affected similarly and the ranking of detrimental effects were growing only one crop each year > growing only one rotation cycle > reducing the number of replications. Reducing time, money, and labor is costly when conducting research.

Technical Abstract:
In recent years, there has been increased interest in long-term, field- scale cropping systems research to protect air and soil quality, to improve pest management, and to increase or maintain growers' profits. However, cropping systems researchers are realizing that these studies require large tracts of land, sizeable labor forces, and substantial inventories of equipment, which make these studies very expensive to conduct. A 6-yr Integrated Cropping Management (ICM) Systems study was conducted from 1985 to 1991 to develop and refine profitable conservation cropping systems for the annual-crop, wheat-growing region of the Pacific Northwest (PNW). This study investigated the effect of tillage, crop rotation, and weed management on crop yield, profitability and economic risk. This ICM study provides the data for the economic and statistical consequences of downsizing long-term field studies. The ICM study was considered to be the ecomplete study in that it contained four treatment replications, was conducted for two crop rotation cycles, and produced every crop every year. The complete study was downsized by reducing the number of treatment replications, reducing the number of crop rotation cycles from two to one, and only growing one crop per rotation each year. Economic and biological data from the downsized experiments were compared to data from the complete study. To the researcher and grower, yield and profit are the most important information collected from these studies. All downsizing of experiments altered economic and biological conclusions similarly; however, reducing replications was least detrimental, using only one rotation cycle was intermediately detrimental, and growing only one crop every year was most detrimental in altering conclusions.